Conventional liquid crystal display panels are widely used as one type of display panel, and are incorporated in electronic devices such as information devices, TV devices and amusement devices. Specific examples of the electronic devices incorporated in the liquid crystal display panels include mobile telephones, PDAs (personal digital assistant), DVD players, mobile game devices, notebook PCs, PC monitors and TV sets.
The configuration of the conventional liquid crystal display panel will be described with reference to FIGS. 8 and 9. FIG. 8 is a schematic plan view showing the configuration of the conventional liquid crystal display panel. FIG. 9 is a schematic cross-sectional view taken along line D-D.
The conventional liquid crystal display panel 100 includes two panel substrates 101 and 102 that are formed of glass. The two panel substrates 101 and 102 are bonded by a frame-shaped seal 103 with a predetermined gap left therebetween in a vertical direction. Liquid crystal 104 is sealed in the space enclosed by the two panel substrates 101 and 102 and the seal 103. A predetermined region substantially in the middle portion of the liquid crystal display panel 100 is a display region 105. The portion outside the display region 105 is a non-display region 106 where a liquid crystal display is not produced.
On the surface of the lower panel substrate (hereinafter also referred to as a “matrix substrate”) 101 of the two panel substrates 101 and 102, a plurality of switching elements such as TFTs (thin film transistor) and pixel electrodes (they are not shown) to which the switching elements are connected are arranged in a matrix. A plurality of scanning signal lines and data signal lines (they are not shown) that drive the switching elements are formed such that they intersect each other. On the other hand, on the upper panel substrate (hereinafter also referred to as an “opposite substrate”) 102, as shown in FIG. 9, the layers of an opposite electrode 107 and a color filter 108 are sequentially formed from the side close to the liquid crystal 104. The matrix substrate 101 and the opposite substrate 102 are arranged such that the pixel electrodes and the opposite electrode 102 face each other, and this results in the formation of the display region 105 described above.
The matrix substrate 101 among the two panel substrates 101 and 102 is formed such that the matrix substrate 101 is larger in planar dimensions than the opposite substrate 102. On the portion of the matrix substrate 101 extending outward more than the opposite substrate 102, a drive IC chip 109 including a circuit for driving the display region 105 is mounted by a COG (chip on glass) method. Here, the drive IC chip 109 is an IC chip into which a drive circuit generating data signals (signals fed to the data signal lines described above) and a drive circuit generating scanning signals (signals fed to the scanning signal lines described above) are integrated.
When the drive IC chip 109 is mounted on the matrix substrate 101 by the COG method, an ACF (anisotropic conductive film) 110 is generally used to achieve the mounting. The technology for mounting an IC chip on a substrate using an ACF is conventionally known (for example, see patent documents 1 to 3).
A procedure for mounting the drive IC chip 109 on the matrix substrate 101 by the COG method will now be described with reference to FIG. 10. The ACF 110 is placed on a predetermined region of the matrix substrate 101. Thereafter, electrode pads 111 formed on the matrix substrate 101 and bump electrodes 112 of the drive IC chip 109 are positioned such that they coincide with each other, and thermocompression bonding is performed by a thermocompression bonding tool 120. In this way, the drive IC chip 109 and the matrix substrate 101 are bonded together.